The role of motility chemotaxis and adhesive factors that bind vibrios to the intestinal mucosa as they relate to the pathogenesis of cholera in animal models is to be studied in hopes that a highly effective antibacterial vaccine can be developed. Its use in combination with antitoxic immunity should provide the optimum prophylaxis against this disease. Previous work has demonstrated that a crude flagellar vaccine administered to female mice at the time of mating passively protects the offspring against oral challenge with homologous and heterologous strains of classical and E1 for Vibrio cholerae. The protective antigen is to be identified and the nature of the immunity elucidated. The latter aspect of the work will be predicated on the assumption that immobilizing antibody plays a crucial role. Since enteropathogenic strains of Escherichia coli produce a disease in man essentially indistinguishable from cholera, parallel experiments will be done with this organism using the isolated ileal loops of rabbits as the animal model. Similar tests will also be done with Salmonella typhimurium, an enteric pathogen with invasive properties.